[PATCH v2 00/18] Introduce DRM_FB_HELPER_DEFAULT_OPS for struct fb_ops

[Christian König]

Am 14.11.2016 um 00:03 schrieb Stefan Christ:
> Hi,
>
> this is the second version of the refactoring work suggested by Daniel Vetter
> in the email:
>
>     https://lists.freedesktop.org/archives/dri-devel/2016-July/113237.html
>
> The define DRM_FB_HELPER_DEFAULT_OPS provides the drm_fb_helper default
> implementations for functions in struct fb_ops. A drm driver can use it like:
>
>      static struct fb_ops drm_fbdev_cma_ops = {
>          .owner          = THIS_MODULE,
>          DRM_FB_HELPER_DEFAULT_OPS,
>          /* driver specific implementations */
>      };

Looks good to me in general, but I've got one question. Why didn't you 
put the owner field into the macro as well?

I have strong doubts that anybody would set anything else than 
THIS_MODULE here.

Regards,
Christian.

>
> The first patch that adds the helper define was already accepted into the
> kernel release candidate v4.9-rc1.
>
> For the new stuff:
>
> Implementing fb_debug_enter and fb_debug_leave callbacks is not without
> pitfalls. It was necessary that driver also implements the mode_set_base_atomic
> callback in struct drm_crtc_helper_funcs. Otherwise it may segfaults. The first
> patch in this series changes that and introduces a check for it.  Now functions
> drm_fb_helper_debug_(enter|leave) can be used without implementing callback
> mode_set_base_atomic. At least the drm drivers armada, ast, qxl, udl and virtio
> are affected by this issue. It seems that the code path was never executed for
> these drivers and nobody noticed.
>
> Refactoring patches for ast, cirrus and mgag200 are dropped.  I leave it to
> Daniel if additional drivers should not be converted.
>
> This series is based on tag v4.9-rc1 and applies cleanly onto drm-next, too.
>
> Kind regards,
> 	Stefan Christ
>
>
> Changes in v2:
> - add patch 'fix segfaults in drm_fb_helper_debug_*'.
>    So functions drm_fb_helper_debug_(enter|leave) can be used
>    unconditionally.
> - add patch 'add fb_debug_* to DRM_FB_HELPER_DEFAULT_OPS' that
>    uses drm_fb_helper_debug_(enter|leave) to implement
>    fb_debug_(enter|leave). It depends on the previous patch
>    to avoid regressions.
> - Drop patches for drm drivers 'ast', 'cirrus' and 'mgag200'
>    since they reimplemented most of the fb_ops callbacks anyway.
> - Also remove fb_debug_(enter|leave) callbacks in fb_ops all
>    refactoring patches.
>
>
> Stefan Christ (18):
>    drm/fb-helper: fix segfaults in drm_fb_helper_debug_*
>    drm/fb-helper: add fb_debug_* to DRM_FB_HELPER_DEFAULT_OPS
>    drm/amdgpu: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/armada: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/bochs: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/fb_cma_helper: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/exynos: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/nouveau: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/qxl: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/rockchip: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/radeon: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/tegra: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/udl: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/msm: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/virtio: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/omapdrm: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/i915: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>    drm/gma500: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops
>
>   drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c        |  8 +-------
>   drivers/gpu/drm/armada/armada_fbdev.c         |  8 +-------
>   drivers/gpu/drm/bochs/bochs_fbdev.c           |  6 +-----
>   drivers/gpu/drm/drm_fb_cma_helper.c           |  6 +-----
>   drivers/gpu/drm/drm_fb_helper.c               |  6 ++++++
>   drivers/gpu/drm/exynos/exynos_drm_fbdev.c     |  6 +-----
>   drivers/gpu/drm/gma500/framebuffer.c          | 12 +++---------
>   drivers/gpu/drm/i915/intel_fbdev.c            |  5 +----
>   drivers/gpu/drm/msm/msm_fbdev.c               |  7 +------
>   drivers/gpu/drm/nouveau/nouveau_fbcon.c       | 16 ++--------------
>   drivers/gpu/drm/omapdrm/omap_fbdev.c          |  5 +----
>   drivers/gpu/drm/qxl/qxl_fb.c                  |  8 +-------
>   drivers/gpu/drm/radeon/radeon_fb.c            |  8 +-------
>   drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c |  6 +-----
>   drivers/gpu/drm/tegra/fb.c                    |  6 +-----
>   drivers/gpu/drm/udl/udl_fb.c                  |  8 +-------
>   drivers/gpu/drm/virtio/virtgpu_fb.c           |  8 +-------
>   include/drm/drm_fb_helper.h                   |  4 +++-
>   18 files changed, 28 insertions(+), 105 deletions(-)
>